He fulfilled the law, and no, adding Gentiles changes nothing other than, when you finally accept it, changing you from heretic to believer. The Law of Moses of the Mosaic covenant is gone. It has been replaced with the Law of the Messiah in the new covenant which had Gentiles added by the kindness of God. And you need to stop with this deranged sacrifices for Gentiles. It shows a complete lack of understanding of scripture, and preaches salvation by works and not by faith.
The Law God promised to "put in the inward parts" is the Law of Moses.
33 But this shall be the covenant that I will make with
the house of Israel;
After those days, saith the LORD,
I will put my law in their inward parts,
And write it in
their hearts;
And will be
their God,
And
they shall be my people.
Jeremiah 31:33.
This New Covenant is between God and Israel. There are no Gentiles named or mentioned in this New Covenant.
There is only ONE Law in existence concerning Israel and God. The Law of Moses originally was written on stone, and it was obeyed from without (externally.) The Law was also type and shadow of the Holy Spirit of Promise. Jesus told His twelve disciples that He would send the Comforter (Holy Spirit), and He would be within them.
16
And I will pray the Father, and he shall give you another Comforter, that he may abide with you for ever;
17
Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you. John 14:16–17.
First thing to recognize and understand about God's promising the Spirit of Truth is that the world cannot receive Him. One of the reasons is the Spirit of Truth is promised to Israel and the world of Gentiles CANNOT receive Him because He is NOT promised to the world but to Israel. To reject this teaching is to reject God who gave it.
The second thing is tied to the first thing: The world "seeth Him not" meaning does not comprehend for the darkness doesn't comprehend the light. And this is the dividing line between God's people (Israel) and the world (Gentiles.)
The third thing is tied to the first and second thing. The world "knoweth Him (the Spirit of Truth) not."
The Comforter who is the Spirit of Truth who is the Holy Spirit of God is that what He, the Spirit of Truth Authored to the children of Israel through Moses is that God's Law will be "put in their (Israel's) hearts (or lives) that is:
#1. their (Israel's) justification. God has declared Israel justified and by declaring Israel "Not Guilty!" (of sin) allows the Spirit of Truth to dwell within the believer because of the atonement bought by the Son with His very own life (life is in the blood.)
#2. By putting His Law in the inward parts of His people the Law/Spirit is now leading and guiding the believer from within the believer who was previously leading and guiding the believer from without (on stone.)
#3. If and when the believer violates the Law of God, the Holy Spirit of Truth from within the believer deals with the believer about sin or sins and almost always brings conviction of sin from within leading ultimately to repentance and restoration of relationship between God and the believer.
This is the present relationship between God and Israel. Beginning with Abram the Hebrew God made covenant promises to Abram that was extended to Abram's biological seed (Gen. 17:7.) Later, God made covenant with the children of Israel (Abram's biological seed) in the desert at the time of the Tabernacle and Moses. With the Advent of the Son of God (Yeshua bar Yosef), the son of Josheph (stepfather) and Mary (biological mother), God offers His Son in the place of the lamb which is sacrificed yearly by the high priest to atone finally and eternally the sins of the children of Israel which leads to the Promised Comforter (Jesus and Joel) who said that the Spirit of God promised to Israel would be the beginning of the New Covenant era which began of the Jewish Feast of Harvest (Pentecost) fifty days from Passover, the same Passover Jesus observed in the upper room with His twelve Jewish disciples. Gentiles were not involved in Passover and were not involved in Jesus' last Passover before His crucifixion and subsequent resurrection from death who conquered sin and death for the Hebrew people of God.
Are you going to tell me this is not Biblical?
These facts above lend credence to what Saul says here:
4 But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law,
5
To redeem them that were under the law, that we might receive the adoption of sons. Galatians 4:4–5.
Or you can show me in the Pentateuch where God says non-Hebrew Gentiles are also under the Law and the high priest offered sacrifices and prayed for the people of God (Israel) and where it says the high priest "sprinkled the Gentile people" with the blood of the sacrifice as he did in sprinkling the blood of the sacrifice upon the children of Israel.
Thus, when it says "Jesus fulfilled the Law" it means the lamb died under the Law to and for the children of Israel under the Law. Gentiles are excluded.